This 24" x 39' roll of Photo Rag Ultra Smooth Matte FineArt Paper from Hahnemuhle features a 100% cotton base with a smooth white surface finish with a bright white point. It features a basis weight of 305 gsm, a thickness of 18.9 mil, a whiteness of 94%, and opacity of 99%, and is both instant drying and water resistant. The paper is also acid free and calcium carbonate buffered. It comes on a 3" core.